Gauging device



Oct. 27, 1959 w. F. ALLER GAUGING DEVICE Filed Aug. 50,v 1955 INVENToR. M j ALM/L BY www( 17am atentv l 2,909,842 Patented. Oct. 27, 1.959

2,909,842 `GAUGING DEVICE.

Willis Fay Aller, Dayton, Ollio, assignor, by mesne assignments, to The Shetiield Corporation, a corporation of Delaware This invention relates to gaging devices and moreparticularly to a device for gaging certaincharacteri'stics of assemblies of iluid reaotant blades and the like;

v It is an object of this invention to provide an apparatus for use in gaging the ow area between blades of. a iiuid reactant blade assembly such. as a turbine nozzle unit or the like, which apparatus is simpleA in construction and application and useful for a long service. life of repeated precision gaging operations. j

It is a further object to provide an apparatus forsimul'- taneously gaging the displacement between blades of a iluid reactant assembly such as a turbine nozzle unit or the like at a plurality of locations along the blade lengths and obtaining a gaging response therefrom determined by the flow area between the blades.

It is. a further object to provide such an apparatus wherein opposed pairs of gaging contacts engage predetermined points on adjacent faces of an adjacent pair of blades and ,areI relatively positioned thereby, each pair of gaging contacts cooperating to control the leakage ilow'through' an associated uidleakage oriceand the orifices being connected to aV common source of under controlled pressure and a common indicator whereby a single indication is provided` indicative of the dis. placement between the blade faces.

It is a further object to provide such an apparatus wherein a'V carrier is provided for a plurality'of gagng Y means, each including a pair of opposed gaging contacts for association with lthe blade surfaces, at least a pair of said contacts being Xed to the carrier whereby the carrier is located relative to the blades during gaging and one of the gaging units including contacts which are movable relative to one another and with respect tothe carrier to accommodate variation inlongitudinal 'curvature of the blades, whereby an accurate gaging response is obtained irrespective of such variations.

It is a further object to provide a unit for gaging the minimum flow area between a pair of adjacent blades of a fluidl reactant blade assembly comprising opposedy pairs of gaging contacts controlling associated orices connected to a common indicator, corresponding contacts in each of the gaging means beingprovide'd for engagement with the trailing edge of one ofthe blades' and each opposed contact being provided for engagement with the adjacent surface of the adjacent blade at a point or" minimum displacement therebetween, whereby by rocking the unit' about the trailing edge of the one' blade a minimum indication is obtained which is indicative of the minimum flow area.

Other objects and advantages of the invention will be' apparent from the following description, the appended claims and the accompanying drawing inwhich, l

Figure 1 is a view of an apparatus embodying the present invention provided for gaging theliovv` area between a. pair of adjacent blades'A ofV a turbine nozzle unit,,

,Figure 2. is a sectional; viewy on line` 24-2'. off Fig- Figure 3 is a fragmentary sectionk taken on line 3-3 of Figure l,

l Figu`re 4 is an enlargedy fragmentary section showing the' `association of'a pair of opposed gaging contacts with a p'air 'of fluid react-ant blades, and l j Figure '5 is a fragmentary View of a turbine nozzle assembly. j

In the manufacture of gas turbine engines' it is eX- trenel'y important .that the total passage area between the 'blades' of 'the iluid reactant assemblies and in particulanbetween the blades of the turbine nozzle unit be within permissible limits. The totalV passage area through' which the propulsive fluid may pass has a bearing onthe eciency ofthe assembled engine. This passa'g'e .area is determined by the radial length of the space' between the blades and the mean yminimum displacement between each adjacent blade pair. The radial extent' ofl the blades is easily controlled during manufacture and usually is gaged at a few points to arrive atan 'average gure.

In determining the mean minimum displacement between adjacent blade pairs itV has previouslybeen necessaryto' take a number o'fseparate measurements atA different radial positions along tlie blade lengths. Through application ofthe present invention it is possible to make a "single measurement between the opposing faces of adjacent bladesV and obtain in a single indication the average minimum displacement betweenthe blade surfaces and the ilowV area therebetween with the radial extentof the passage area being known. Thus, the number ofrea'dings'ds .materially reduced and the number of calculations involved are minimized. For example, in one previous" application it has been necessary to make a' number of individual measurements of the minimum displacement' between each adjacent pair of blades at different radial. positions. This involves a number of recordings and' a number of calculations to determine the minimum flow area between only one pair of blades. The advantages of the single reading `provided by the present invention willV be obvious when the number of bladepairs which must be gaged' is visualized.

In the illustrated embodiment of the present invention an apparatusy is providedA giving a single indication determined'V by the relativev displacements between three pairs of gaging contacts, each pair cooperating -with a pointalong the trailing edge of'one blade and the point on the'opp'osing surface of the adjacent blade at amumdisplacement therefrom.

'A vfragment of a turbine nozzle unit is shown in Figurel 5. The radially outer shroud ring is indicated at 10 and the radially inner ring at 11 with a yseries of blades extending' therebetween. the minimum displacement between blades 12 and 14 is gaged" at locations 15, 16*A and 17 by means of the apparatus shown in the other figures. Three gaging means` or assemblies 20, 21 and 24are mounted on a common cariierZS. Carrier 25 is manipulated by the operator through` means of a handle 26. .Each of the gagingas-y Asecondconta'c't' i's carried by-a'bell crank 37V pivot'eclv at138 onrnemberr 3'1'. A controllableleakage' oritice'uriit In this exemplary application 3 4'@ which can be of the type disclosed in Patent Number 2,691,827, issued October 19, 1954, is xed in member 3l by means of a set screw 4l.

Gaging cartridges such as that indicated at 40 provide a fluid leakage orifice in the cartridge body which is controlled by movements of an extended contactor 45.

In the assembly 24 contactor 45 engages bell crank 37 and as it will be seen that the leakage through cartridge 4l? and conduit 5l) will be determined by the relative displacement between gaging contacts 30 and 36 and the distance between the blade surfaces engaged.

Gaging assembly 24 is at one side of the apparatus as seen in Figure 1. Assembly at the other side of the apparatus is similar in construction, being provided with one gaging contact fixed relative to carrier and another contact 55 pivoted on a member 56 which supports a second fluid leakage orifice unit 57. The contactor 58 of this orifice unit is controlled by movement of a bell crank 59 positioned by contact 55. With gaging assemblies 20 and 24 having xed contacts for engaging the trailing edge of the blade carrier 25 can be swung about the trailing edge during gaging.

Figure 4 illustrates the association of the gaging contacts of the assembly 24 with blades 12 and 14, which association is'typical of the assemblies. It will be seen that contact 36 engages the surface of blade 14 and notch-like contact engages and receives the trailing edge of blade 12.

Due to the fact that the blades may be bowed in a lengthwise direction to varying degrees, the central assembly 2l is constructed as seen in Figure 2 for floating movement relative to the other gaging assemblies and to carrier 25.

In this case gaging contact 60 is fixed to member 61 and serves to pivot the member about an axis 62 to bodily position orice unit 65 relative to carrier 25. A spring bias 64 is provided to maintain contact 60 in engagement with the trailing edge of the blade. Contact 67 on bell crank 68 is also pivoted about axis 62 and positions the contacting plunger 70 of unit 65 in accordance with the relative displacements between contacts 60 and 67 during gaging. Spring 7l situated between bell crank 68 and member 61 serves to urge contact 67 into engagement with the surface of blade 14 in this exemplary application.

Thus in application the fixed contacts of assemblies 20 and 24 engage the trailing edge of blade 12 and allow rocking movement of carrier 25 thereabout. Contacts 55 and 36 of assemblies 20 and 24 respectively are spring urged into engagement with the surface of blade 14. In assembly 2l both gaging contacts 60 and 67 are relatively movable on carrier 25 and can seek their own position, accommodating for variations in longitudinal curvature of the blades to allow a gaging of the displacement between the blades at a desired location intermediate the blade ends.

Air is supplied for gaging from a connection at 75 adapted for connection to a source of air under pressure. The supplied air ows through a single indicator 76, a passage 77 and through branch passages or conduits 78, 79 and 5G to gaging cartridges 57, 65 and 40 respectively. The indication obtained is determined by the sum of the flows through the gaging cartridges and the mean displacement between the gage contact points.

in practice where it is desired to measure the minimum flow area the carrier 25 is rocked about the fixed contacts engaging the trailing edge of blade l2 until a minimum reading is obtained on indicator 76. This indication will be determined by the mean minimum displacement between the blade surfaces at the gaging locations, providing a single indication of the ow area between an adjacent pair of blades. The indicator utilized can be of the type illustrated having an internally tapered verticallyv disposed transparent flow tube and a float movable along the tube in response to the velocity of ow which is in.

d turn controlled by the leakage through the fluid leakage orifices in the gaging cartridges and the displacements between the associated pairs of gaging contacts.

Thus it is seen that an apparatus has been provided for rapidly obtaining in a simple manner a single gaging response indicative of the flow area between an adjacent pair of blades of a fluid reactant blade assembly. The number of operations required has been materially reduced and recordings and computations have been minimized. The apparatus is simple and rugged in construction and is useful for long service life of repeated gaging operations.

While the form of apparatus herein described constitutes a preferred embodiment of the invention, it is to be understood that the invention is not limited to this precise form of apparatus, and that changes may be made therein without departing from the scope of the invention which is dened in the appended claims.

What is claimed is:

l. Apparatus foruse in determining the effective flow area between an adjacent pair of fluid reactant blades of airfoil section in an assembly such as a turbine nozzle unit or the like, comprising a plurality of gaging means, each gaging means having a pair of relatively movable opposing gaging contacts including a notch-like contact for engaging the trailing edge of one blade and an oppositely facing curved contact for engaging the convex surface of the adjacent blade, means responsive to the displacement between each cooperating pair of contacts and the opposing surfaces of an adjacent pair of blades at one point along the blade lengths, a carrier, means for supporting said gaging means on said carrier in relative spaced relationship for gaging association with spaced points along the blade lengths, said supporting means disposing the respective pairs of contacts for movement in parallel gaging planes and providing for floating movement to accommodate variations in longitudinal blade conguration, and indicating means connected to said plurality of gaging means providing a single indication determined by the minimum displacement between the blade surfaces at a plurality of points therealong and the ow area therebetween. v

2. Apparatus for measuring the displacement between an adjacent pair of fluid reactant blades of an assembly such as a turbine nozzle unit or the like, said apparatus comprising a plurality of gaging means for gaging the displacements between adjacent surfaces of a pair of adjacent blades at a plurality of locations along the blade lengths, a carrier for supporting said gaging means in relatively spaced relationship along said blades, each of said gaging means including relatively movable first and second gaging contacts for association with a predetermined point on the surface of one blade and the opposing surface of the other of said adjacent blades at a point of minimum displacement from said one point, the second gaging contact of at least a pair of said gaging means being fixed to said carrier whereby the carrier is located relative to the blades during gaging, another of said gaging means being mounted on said carrier for floating movement to accommodate variations in lengthwise curvature of the blades, and indicating means connected to said plurality of gaging means providing a single indication responsive to the displacement between the pairs of gaging contacts as determined by the flow area between the blades.

3. Apparatus for measuring the displacement between an adjacent pair of fluid reactant blades of airfoil section in an assembly such as a turbine nozzle unit or the like, said apparatus comprising a carrier, gaging contact means supported for relative movement on said carrier including a notch-like receiver for engaging the trailing edge of one of the blades whereby the carrier is located for pivoting j movement about the blade edge and an oppositely facing gaging contact for engaging the opposing convex surface arcuately curved, fluid leakage gaging means on said carrier controlled by relative movement of said contacts, and air supply means leading to said fluid leakage gauging means adapted for connection to -a source of air under pressure and an indicator responsive to the leakage therethrough, whereby said carrier can be pivoted about an axis established by engagement of said receiver with the trailing edge of one blade 4as the curved gaging contact follows the opposing surface of the adjacent blade and the minimum displacement between the blades determined when the minimum indicator reading is obtained.

4. Apparatus for measuring the displacement between an adjacent pair of uid reactant blades of an assembly such as a turbine nozzle unit or the like, said apparatus comprising a plurality of gaging means, each gaging means including a iirst gaging contact for engagement with a surface on one of the blades at one predetermined point therealong and a second gaging contact for engagement with the opposing surface of the other of said adjacent blades at the point of minimum displacement from said one point and a iiuid leakage oriiice controlled by the relative displacement between the gaging contacts during gaging, `a carrier supporting said gaging means in relatively spaced relationship along the blades, at least a pair of said gaging means each including means iixing one of the gaging contacts and the associated leakage orice to said carrier and carrying the other contact for movement relative thereto, whereby said carrier is located relative to said blades and the minimum displacement between the blades at a pair of points is gaged, means in a third of said gaging means carrying the associated contacts for movement relative to one another and relative to said carrier and mounting the leakage oritice in xed relationship to one of the associated contacts for movement therewith, whereby a third minimum displacement between the blades is gaged and variations in lengthwise curvature of said blades is accommodated, and air conduit means connected to each of said leakage orifices `adapted for connection to a source of air under controlled pressure and an indicator responsive to the total iiow through the plurality of leakage orifices and the displacements between the pairs of gaging contacts as determined by the ilow area between the blades.

5. Apparatus for measuring the displacement between an adjacent pair of fluid reactant blades of an assembly such fas a turbine nozzle unit or the like, said apparatus comprising a plurality of gaging means, each including a pair of relatively movable gaging contacts for engagement with a surface of one of the blades at one predetermined point therealong and with the opposing surface of the other of said adjacent blades at the point of minimum displacement from said one point, a uid leakage oriiice in each gaging means controlled by the relative positions of the associated pair of gaging contacts, a carrier for supporting said gaging means in relatively spaced relationship along the blades, at least a pair of said gaging means including means iiXing one of the associated gaging contacts and the corresponding fluid leakage oriiice to said carrier and carrying the other contact for pivoting movement relative thereto, whereby said carrier is located relative to said blades and the leakage through the respective orifices is determined by the minimum displacement between the blades at the locations gaged, means in another of said gaging means carrying the associated gaging contacts for pivoting movement relative to one another and relative to said carrier and mounting the associated leakage orifice in fixed relation to one of the associated gaging contacts for pivoting movement therewith, whereby variations in lengthwise curvature of said blades is accommodated, the pivot axes for the various gaging contacts being parallel, air conduit means connected to the plurality of gaging orifices and adapted for connection to a source of air under controlled pressure and an indicator responsive to the total flow through the orifices as determined by the relative displacement between the pairs of gaging contacts and the tiow area between the blades.

6. Apparatus for measuring displacement between an adjacent pair of iiuid reactant blades of airfoil section in an assembly such as la turbine nozzle unit or the like comprising a carrier, a plurality ofgaging assemblies, each assembly including a contact following a notch-like depression for locating engagement about the trailing edge of one blade and a relatively movable oppositely facing curved contact for engagement with and movement along the convex surface of the adjacent blade as the apparatus is rocked about the notch-like depressions, means in each assembly carrying the associated contacts for relative movement toward and from one another in accordance with the dimension gaged, means mounting said assemblies on said carrier in relatively spaced relationship for association with the blades at spaced locations therealong and disposing the cooperating pairs of contacts for movement in parallel gaging planes, said mounting means including means carrying at least one of said assemblies for floating movement relative to the carrier and the other of said assemblies, and gaging means operatively connected to each of said assemblies responsive to the relative contact positions in each assembly to provide a single response determined by the composite displacements between the blades at the spaced locations.

References Cited in the file of this patent UNITED STATES PATENTS 1,806,756 Harding May 26, 1931 1,938,216 Damerell Dec. 5, 1933 2,028,503 Doherty lan. 2l, 1936 2,080,941 Hutchinson May 18, 1937 2,306,469 Rupley Dec. 29, 1942 2,348,095 Roby May 2, 1944 2,431,087 Subber Nov. 18, 1947 2,571,917 Mennesson Oct. 16, 1951 2,594,077 Schulze Apr. 22, 1952 2,622,331 Haines Dec. 23, 1952 2,638,680 Baker May 19, 1953 2,691,827 Aller Oct. 19, 1954 

